Microsoft Win32k Privilege Escalation Vulnerability
Microsoft Win32k fails to properly handle objects in memory causing privilege escalation. Successful exploitation allows an attacker to run code in kernel mode.
- Vendor
- Microsoft
- Product
- Win32k
- CVSS
- 7.8
- EPSS (exploit probability)
- 4.2%
- Status
- kevransomware use
- CISA patch-by (BOD 22-01)
- Added to KEV
Is CVE-2019-0859 being exploited?
Yes. CISA added CVE-2019-0859 to its Known Exploited Vulnerabilities catalog on . CISA only lists a CVE when it has reliable evidence of exploitation in the wild. CISA marks it as known to be used in ransomware campaigns.
FIRST's EPSS model puts the probability of exploitation activity in the next 30 days at 4.2% (scored November 3, 2026).
- CISA KEV[ LISTED ]
- ENISA EUVD (exploited)[ — ]
- CIRCL KEV[ — ]
Catalog snapshot 2026-11-13. Full cross-catalog view: /kev-comparison
CVE-2019-0859 timeline
Every event links to its source. Catalog dates are each catalog's own; day offsets count from NVD publication. Data: JSON
What to do
CISA required actionApply updates per vendor instructions.
US federal civilian agencies must remediate by (181 days after listing) under BOD 22-01. Everyone else: that deadline is a sensible upper bound, not a target. Vendor guidance and the NVD record are linked under Source above.
Other Microsoft Win32k CVEs we track
| CVE / Vulnerability | Severity | CVSS | EPSS | Added to KEV |
|---|---|---|---|---|
| CVE-2016-0165 Microsoft Win32k Privilege Escalation Vulnerability | [ HIGH ] | 7.8 | 13.7% | |
| CVE-2023-29336 Microsoft Win32K Privilege Escalation Vulnerability | [ HIGH ] | 7.8 | 41.2% | |
| CVE-2015-2360 Microsoft Win32k Privilege Escalation Vulnerability | [ HIGH ] | 8.8 | 14.8% | |
| CVE-2018-8589 Microsoft Win32k Privilege Escalation Vulnerability | [ HIGH ] | 7.8 | 3.0% | |
| CVE-2014-4113 Microsoft Win32k Privilege Escalation Vulnerability | [ HIGH ] | 7.8 | 86.6% | |
| CVE-2021-41357 Microsoft Win32k Privilege Escalation Vulnerability | [ HIGH ] | 7.8 | 1.5% | |
| CVE-2021-40450 Microsoft Win32k Privilege Escalation Vulnerability | [ HIGH ] | 7.8 | 1.5% | |
| CVE-2013-3660 Microsoft Win32k Privilege Escalation Vulnerability | [ HIGH ] | 7.8 | 39.3% |